Does "GM" make RWD axles any more? I thought that was the whole point of AAM--GM sold-off their axle/gearmaking the same way they sold off AC-Delco.
Yes, GM actually started making an axle again a couple years ago, but I don't know anything about it. It's made at the plant in Grand Rapids, MI. I THINK it's a rear axle, but I'm not sure.... it might be the IRS axle they use in the new SUV's, but that's a completel guess on my part.
GM didn't sell AC Delco, they sold Delphi. GM has bought/sold/folded-into so many brands/companies it's a bit hard to keep straight.
The 8.5", the 9.5", and the 10.5" ring-gear axles are AAM products. I think there's an 11.5 axle used on the C3500HD that's a Dana product. But I don't think there's a "GM" axle in the bunch.
The 11.5" in the 3500HD is a Dana 80. The rest are GM designs, formerly produced by GM, and now produced by AAM. There is also an 11.5" AAM that's roughly based on the 10.5 14BFF.
Some vans did, and maybe still do get Dana axles.... my uncles 3500 van has a Dana FF axle. I don't recall the year, but it's probably mid-oughts.
This composite shaft was on a vehicle with a 9.5 AAM axle--but how/why GM selects which driveshaft construction goes with which powertrain is way beyond my pay-grade.
Any recollection what year that truck was, where you found the composite shaft?
I don't know how they determine it either. I suppose it's a balance between weight of the finished shaft, length and torque requirements.
It's my opinion that many aluminum AAM shafts are garbage. I'm very happy with my steel shaft. I was just looking at it the other day.... The front u-joint is still fine after almost 300K miles. The rear has a little slop. It's been replaced once before.